This invention relates to an apparatus for efficiently cleaning polluted waste gases from an industrial process, and more particularly to an apparatus known as a regenerative thermal oxidizer (hereinafter an RTO).
It is desirable to clean polluted gases which exit an industrial process so as to emit or release clean gases to the environment.
There are many devices which provide cleaned gases. See for example, U.S. Pat. Nos. 3,172,251; 3,914,088; 3,997,294; 4,280,416; 4,454,826; 4,650,414; 4,678,643; 4,850,862; 4,867,949; 5,016,547; 5,024,817; 5,163,829; and German Patent 133,704. See also European patent document No. 0548630A1, which discloses a regenerative thermal oxidizer.
Incineration systems may employ a combustion chamber to burn or incinerate incoming polluted gases and related delivery and valving mechanisms. There is an inlet to receive incoming polluted gas and a structure or mechanism to direct the incoming gas to a combustion chamber. In some systems the incoming gas passes through heat exchanger material (which has been heated) before it reaches the combustion chamber to raise the incoming gas temperature. In the combustion chamber the gas is burned or cleaned and the cleansed or outgoing gas is directed, sometimes, through heat exchanger material, where it gives up heat and then to an outlet for outgoing cleaned gas. The heat exchanger materials are used to transfer heat from the outgoing gas to the incoming gas.
It has been found to be desirable to segment the combustion chamber construction and sequentially pass incoming gas to selected segments and receive outgoing gas from other, generally oppositely positioned, selected segments. This is sometimes done using a distribution device which may be rotary.
It has also been found to be desirable to purge a segment before cleaned or outgoing gas passes through that segment. The purge gas is usually from external sources. Rotary valving for the sequential delivery of incoming and purge gases and expulsion of outgoing gas is shown. Also see for example U.S. Pat. Nos. 4,280,416 and 5,016,547.
European Patent document 0548630A1 discloses an RTO device where the purge gas is drawn from the cleaned outgoing gas and exits an upper section via a rotating segment that is as large in radius as the RTO housing.
It is believed that the European unit embodies many desirable features and while generally acceptable can be improved in efficiency and for use in the United States of America.
Therefore, it is an object of this invention to provide improvements to a European type system so as to render it more efficient and more acceptable in the U.S.
This and other objects of this invention shall become apparent from the following description and appended claims.